Servenet 
http://www.servenet.org/ 
SERVEnet.org is the premier website on service and volunteering. Through SERVEnet, users can enter their zip code, city, state, skills, interests, and availability and be matched with organizations needing help. SERVEnet is also a place to search for calendar events, job openings, service news, recommended books, and best practices. YSA's commitment to America's Promise is to have volunteer opportunities on SERVEnet for every zip code in America. 

VolunteerMatch 
http://www.volunteermatch.org/ 
VolunteerMatch is a nonprofit organization with a mission to help everyone find a great place to volunteer, and offers a variety of online services to support a community of nonprofit, volunteer and business leaders committed to civic engagement. Interested volunteers can enter their ZIP code on the VolunteerMatch home page to quickly find local volunteer opportunities posted by nonprofit organizations throughout the United States. 

SocialStep 
http://www.socialstep.com/givingback/ 
It's important that we remember to keep our communities in mind when we are building our personal and professional empires. The information below could give you some ideas. 

Points of Light Foundation 
http://www.pointsoflight.org/ 
The Points of Light Foundation & Volunteer Center National Network engages and mobilizes millions of volunteers who are helping to solve serious social problems in thousands of communities. Through a variety of programs and services, the Foundation encourages people from all walks of life — businesses, nonprofits, faith-based organizations, low-income communities, families, youth, and older adults — to volunteer.